3D stereoscopic display is a type of display that provides the user with two or more images (e.g., a left and a right eye view) in order to achieve a three-dimensional effect. Different technologies exist for 3D stereoscopic displays, such as passive glasses (anaglyph or polarizer), active shutter glasses, and autostereoscopic (spatial multiplexing or temporal multiplexing).
Autostereoscopic displays provide users 3D experience without the use of special headgear or glasses. Such 3D experience is achieved through binocular parallax, which is the apparent difference in position of an object as seen the left and right eyes while the head remains unmoved. Autostereoscopic displays include spatial multiplexing (parallax barrier and lenticular arrays) and temporal multiplexing (directional backlight).
Most autostereoscopic displays produce 3D images that can only be seen within a narrow viewing zone in front of the displays. The range of useful distances is limited by the need that both eyes appear inside the corresponding “sweet spot” to see 3D images. Furthermore, it can be difficult for a viewer to find the optimum position for the best 3D viewing experience, which usually must be found through a trial-and-error approach of the viewer moving to different viewing positions. Accordingly, a need exists for assisting viewers in positioning themselves for viewing 3D autostereoscopic displays.